With the proliferation of endoscopic surgery, it has been realized that there are many procedures typically performed in open surgery which can be performed endoscopically. In endoscopic surgery, a trocar, which is a pointed piercing device, is inserted into the body with a cannula placed around the trocar. After the trocar pierces the body cavity walls, it is removed and the cannula remains in the body. Through this cannula, endoscopic procedures can be conducted. Generally, the endoscopic procedures are performed under insufflation. Some of the more typical endoscopic procedures have included gall bladder removal, tissue repair, and sterilization procedures such as occluding of fallopian tubes.
Surgeons realize that it may be possible to perform additional procedures endoscopically, once the proper materials and mechanisms become available for performing these procedures. One of the more basic, and quite logical extensions of current endoscopic procedures has been focused on the repair of hernias. It is realized that to have the capability of performing hernia repair endoscopically will benefit the medical community in many ways. Specifically, it is realized that endoscopic hernia repair will allow the patient to recuperate more rapidly, and without the more than likely extensive physical therapy currently practiced as a result of a hernia repair performed by open surgery.
Moreover, it is realized that hernia repair procedures may contain aspects which are applicable in other procedures. For instance, if it is possible to cover, or reinforce and constrain a hernia, it may be possible to apply this procedure to other vessels or organs, in a similar manner. Also, it is realized that once a device becomes available wherein hernias can be repaired, many of the functional components of the hernia repair device will be useful in other devices capable of performing other procedures. Also, naturally, these mechanisms may be useful for procedures in which open surgery is performed.
In response to the above described needs, a number of surgical instruments have been developed for use in endoscopic stapling procedures. One such device, copending U.S. patent application Ser. No. 759,014, filed Sep. 12, 1991, now U.S. Pat. No. 5,246,156, expressly incorporated in its entirety by reference herein, discloses a surgical stapler having a rigid, rotatable shaft containing a stack of staples aligned in a horizontal plane with respect to the shaft. This mechanism has proven quite effective in performing endoscopic surgical procedures; it does not, however, offer means for articulating the tip of the shaft containing the staples in response to a surgeon's need to alter the orientation of the device once it has been inserted into the patient.
Copending U.S. patent application Ser. No. 959,184, now U.S. Pat. No. 5,381,943, also expressly incorporated in its entirety by reference herein, discloses an endoscopic surgical device which includes an articulating tip allowing the surgeon to articulate a staple cartridge after the device has been inserted into the patient. The staple cartridge includes a stack of staples oriented in a vertical plane, which allows for a more efficient packing of staples in the device.
Although the articulation device of the aforedescribed application is effective in providing articulation of the tip of the shaft, it is limited to providing a predetermined number of angles of articulation by use of a ratchet mechanism. Occasionally, the ratchet mechanism may bind and become difficult to operate smoothly.
It would, therefore, be useful to provide an endoscopic surgical instrument that is capable of having an articulatable tip that could be rotated about its longitudinal axis in a plurality of angles of articulation with respect to the shaft. Additionally, a significant advance in the art would be realized if a new articulation device could be developed to better solve the aforementioned problems of ratchet-type articulation.